Electric water-heater



H. W. CHRISTIAN.

ELECTRIC WATER HEATER.

APPLICATION man SEPTJ, |920.

1,400,526. Patented Dec. 20, 1921.

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H. W. CHRISTIAN. ELECTRIC WATER HEATER.

APPLICATION FILED SEPT. 7, 1920. 1,400,526, Patented Dec. 20, 1921.

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PATENT OFFICE.

HERBERT W. CHRISTIAN, F DETROIT, MICHIGAN.

ELECTRIC WATER-HEATER.

Specication of Letters Patent.

Patented Dec. 20, 1921.

Application led September 7, v1920. Serial No. 408,606.

Wayne and State of Michigan, have invent-v ed certain new and useful Improvements in Electric Water-Heaters, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to an instantaneous electric water heater and has special reference to that class of heaters wherein water flows exteriorly of an electric heating element in contradistinction to flowing through an electrically heated element. In the tormer it is possible to provide a large heating surface and spread the water out as a film so that it may be more quickly heated, whereas in the latter the volume of water is such as to prohibit instantaneous heating under ordinary conditions.

The primary object of my invention is to provide an electrically operated heating apparatus through which water may. flow in the form of a film and be quickly and economically heated. The water may be conducted about a multiplicity of heating elements or caused to flow against the walls of a cylindrical heating element, either form permitting of the apparatus being. compactly constructed, especially when including a reservoir about which the heating element or elements may be disposed.

Another' object of this invention is to provide an electrically operated water heating apparatus wherein a float, within a reservoir, controls the use of current in connection with the apparatus, thus practically avoiding waste of current, over boiling or the generation of steam.

A further object of my invention is to rovide an electric water heatinv a aratus b wherein the parts are constructed so as to be easily assembled and permit of easy acf cess being had to the various parts of the apparatus for cleaning or repair purposes, it' necessary, and the construction entering into the apparatus will be hereinafter described and then claimed.

Reference will now be had to the drawings, wherein- Figure 1 is a vertical sectional view of the apparatus, and

Fig. 2 is a horizontal sectional view taken on the line 2l- 9, looking in the direction of the arrows.

ln the drawings, the reference numeral 1 denotes a cylindrical casing having a bottom wall 2 and a detachable cover 3, said cover having a central opening providing clearance for a cylindrical reservoir at which may rest on the bottom wall 2 or bepsupported therefrom by feet 5. The upper 'end of the reservoir protrudes above the cover 3 and is normally closed by a detachable lid 6. This lid and the bottom wall of the reservoir mayhave outlet pipes 7 and the lid may have a conventional form of safety valve 8. Either of the outlet pipes'7 may be used for withdrawing warm water from the reservoir 4 and the valve 8 is simply provided as a safety factor.

In the casing 1 is placed a lining 9 preferably madeof asbestos or any suitable insulation material and suitably supported at the upper and lower. ends of the lining is an upper water chamber,10 and a lower water chamber l1. These chambers are somewhat in the form of drums which surround the reservoir +L and the lower water chamber 11 is adapted to receive cold water from a suitable supply pipe 12 which may be providedwith a strainer 01 filter 13 of a conventional form.

Connecting the upper and lower water chambers and extending therethrough are electrically operated heating elements 14, preferably in the form of circumferentially disposed vertical tubes containing resistance coils 15 electrically connected in series, as at 16, and having leading out wires 17 and 18. The space between the lower water chamber 11 and the bottom wall 2; provides sufficient clearance for. the series connections and the leading out wires 17 and 18 may extend through the cover 3 or any insulator connected to the casing or its cover. The walls of the vertical tube's are adapted to be heated by the resistance coils and vsaid coils may be suitably arranged and supported within the tubes.

Connecting the lower wall of the upper Water chamber 10 to the upper wall of the lower water chamber 11 are water conduits 19 which surround the electric heating elements and provide cylindrical passages 2() for water which Hows, under pressure, from the lower water chamber 11 to the. upper water chamber 10. The walls of the conduits 19 are very close to the walls of the heating elements so that the passages 20 simply accommodate 'small quantities or films of `waterwhich contacting with the walls ofthe heatingelements are heated by on a diiferentshape so as -t'o maintain the waterina film to be easily attacked. In such form it is possible to heat the water to a high temperature` before/it escapes from a conduit into the upper water chamber 10.

Surrounding the reservoir 4 and connecting theupper 4and lower water chambers l() and 11 respectively isa shell 40 and between said shell ,and the lining 9 is placed insulating material 21, as asbest-os 01 mineral wool. The insulating material is packed around the water conduit 19 and assists in maintaining the water conduitsinzposition' relative toithe upper and lowerchambers and the shell 40connectin'g said chambers.

The bottom wall of the upper water chamber 10 has a series of slots or openings 22 at the wall of the. reservoir 4 so that the contents of the upper chamber `10 may flow downwardly between the shell 40 andl lSaid reservoir. The wall ofthe reservoir, ad-

jacent the lower water chamber 1l has a plurality of openings 23 permitting of the watery flowing into the bottom of the reservoir where it accumulates and may have heat conducted thereto, through the reservoir wall by the heated water in the passage ofthe shell 40.

Slidable in the reservoirv 4.is a fioat 24 having a rod 25 sliding through a conventional form of stuliing box 26 carried by the lid 6. `The downward movement of the fioat 24 is` limited by a stop 27 onthe. bottom of the reservoir 4 and the upward movement of, said float is limitedby a pin or stop 28 carried by the rod 25 and adaptedv to impinge againstthelid 6. The float 24 isof a conventionalhollow form buoyant on the water within the reservoir and said float may have guide or packing rings 29 bearing' againstthe reservoir walls untilthe float is elevatedwh en water may, pass above the float in a plurality' of rooves 30 in the reser-y voir wall. The .packlng rings or the recess may not benecessary when the heated water is withdrawn from the bottom of the reser- Voir.

The float rod 25 is adapted to actuate an electric switch which for `the purposes of illustration'has been shown as including an insulated support 3lfor resilient contact members 32 adapted to be engaged by a blade 33-coperating withthe contact members 32 in providing a knife switch. One of the contact members 32 iswco'rinected to the leading out wire 18 and the other conf t tact member 32 has a4 leading out wire34 which follows the leading out-wire 17 to a suitable source of electrical energy. as an ordinary electric lighting circuit.v

The switch blade 33 is carried by a fulcrumed arm 35 preferably supported by an upright 36l of the lidG, and the arm 35 has a pin and slot connection 3T with the upper ylendfof:- the A`iioa-t .rod25. t rAs shown, the arm 35 is preferably hollow or in the form of a receptacle containing a counterbalance weight 38 which may be in the form of a movable body of liquid, as mercury. The

arm 35 is disposed so thatI it is overbalanced,

especially by the counterweight, with the switch closed, and after a predetermined movement ofthe float 24the rod 25 thereof elevates the inner end of the arm 35 causing the counterweight to shiftto the outer end of the arm and thus produce a'quick opening of the switch. This will prevent arcing at the contacts-of the switch that. otherwise might occur ifthe arm is slowly actuated by the float rod, but I have simply illustrated this form of switch and arm as an example of a quick make and break circuit controling device that may be actuated, directly or indirectly, from the float rod. It is believed that in the majority of installations the switch will be located at some more convenient place than above the apparatus for in all probability the apparatus will be placed at an elevation to permit of water flowing by gravity from the reservoir.

The apparatus may be designed to hold a predetermined quantity of hot water and the flow of water to and from the apparatus will be regulatedlor controlled by ordinary valves (not shown). Should the kapparatus contain a quantity of cold water the water is drained off and a fresh supply of water admitted to the apparatus. W'hen the cold water is drained ofi' the float 24 is lowered and the electric switch closed so that. the inowin water willbe heated. The heating of tie water will continue as long as water is withdrawn fromvthe apparatus and to discontinue heating, water it is only neces sary to shut off the outiowing warm water `atwhich time the supply of water in the reservoir will raise the iioat and open the switch, The apparatus will then remain` filtered, and while in the drawings there is i' illustrated a preferred embodiment of my invention, I, would have it understood that the structural elements are susceptible te such changes as fall within the scope of the appended claims.

What I claim is y 1. A water heating apparatus comprising an electric heating element, means to maintain a ilm ot' water about said heating element, and means actuated by a predetermined quantity of heated water'to control the operation of said electric heating element.

2. A water heating apparatus as in claim l, characterized by the last mentioned means including a reservoir and a float actuated switch. y

3. A water heating apparatus as in claim l, characterized by the iirst mentioned means including concentric tubular members between which the water flows.

l. A water heating apparatus comprising upper and lower water chambers, conduits connecting said chambers so that water may flow from one chamber to the other, and electrically operated cheating elements in said conduits.

A water heating apparatus as in claim 4, characterized by the heating elements being approximately the size of said conduits to cause the water to iiow as a film between said conduits and said heating elements.

6. A water heating apparatus :as in claim l, characterized by a reservoir about which the chambers and conduits are disposed and supply water thereto.

7. A water heating apparatus comprising a reservoir, upper and lower walter chambers. a conduit connecting said chambers and through which water flows from onel chamber to the other, an electrically operated heating element in said conduit and against which water is maintained inthe form ot' a Hlm by said conduit, and means adapted to conduct water from one of said chambers to said reservoir and against the outer wall of said reservoir.v

F4. A water heating apparatus as in claim T. characterized by a switch controlling the operation of said heating element, and means in said reservoir adapted to actuate said switch. p

9. A water heating apparatus comprising a reservoir, upper and lower water chambers about said reservoir, conduits disposed about said reservoir and communicating with said chambers, electrically operated heating elements in said conduits and con,-

nected in series, a switch in circuit with said heating elements, means establishing communication between said reservoir and one of said chambers so that said reservoir may receive warm water from said chamber, and a oat in said reservoir adapted to actuate said switch.

10. A water heating apparatus asin claim 9, characterized by the said means including a shell about said, reservoir to provide a water passage against the walls otsaid reservoir.'

1l. A water heating apparatus comprising a reservoir, a shell, a conduit and a heating element disposed in parallelism to provide passages between said reservoir and said shell and between said conduit and said heating element in which water may flow as a ilm and enter said reservoir; and means controlling the operation of said heating element.

12. A water heating apparatus including an electric heating element, and means to cause a film of water to flow longitudinally of said electric heating element against the outer 7alls thereof soas t-o be heated by conduction during its tlow against said electric heating element.

13. An instantaneous water heater comprising an electric heating element, means to conduct a film of water against said heating element and means constructively arranged to be actuated by water within the heater to4 control the operation of said electric heating element.

14. Means adapted for heating a liquid comprising walls providing a passage so narrow that the liquid in the passage is in the form of a film that may be heated by conductionthrough one of said. walls, and electric heating means for one of said walls.

l5. An instantaneous liquid heater comprising a wall, means to maintain a ilm-like formation of liquid at the wall to be heated thereby, and electric heatingmeans for the wall.

In testimony whereof I aix my signature in presence ot' two witnesses.

HERBERT W. CHRISTIAN.

Witnesses lViLLIAM C. BLYTH, ANNA M. Dorm. 

